Answer:
The mol fraction of sucrose in an aqueous solution at 20°C is 0.114
Explanation:
Step 1: Data given
The vapor pressure of water above the solution is 2.0 mmHg
The vapor pressure of pure water at 20 °C is 17.5 mmHg
Step 2: Calculate the mol fraction of sucrose
Psolution = (χsolvent) (P°solvent)
⇒with Psolution = the vapor pressure of the solution is 2.0 mmHg
⇒with χsolvent = the mol fraction of sucrose = TO BE DETERMINED
⇒with P°solvent = the vapor pressure of pure water at 20 °C =17.5 mmHg
2.0 mmHg = X * 17.5 mmHg
X = 2.0 mmHg / 17.5 mmHg
X = 0.114
The mol fraction of sucrose in an aqueous solution at 20°C is 0.114